This application requests R13 funds for the 2020 conference of the American Psychopathological Association (APPA) on the topic ?Substance Use, Substance Use Disorders.? This topic is timely due to the current U.S. opioid crisis, changing cannabis laws, attitudes, and growing use of cannabis, and increases in adult drinking, especially among women. Founded in 1910, the APPA has as its mission to support the investigation of disordered behavior, including its biological underpinnings and psychosocial substrates, and to promote the development of junior scientists. The APPA holds a yearly scientific conference focusing on a different specialized topic each year, providing an opportunity to address particular topics in depth. Presenters and attendees are widely diverse in terms of disciplines and areas of expertise, making the APPA meeting a forum for integrating different perspectives. The unique all-plenary format for APPA conference presentations stimulates an exchange of information, concepts, methods, new findings, current controversies, and pressing gaps in knowledge that results from the diversity of the presenters and the audience. The aim of the 2020 conference is two-fold. First, the conference aims to advance the field of substance abuse research and related areas by providing an exciting scientific meeting in this unique, all-plenary format, with the goal of impacting the field by stimulating new research directions and collaborations. Second, for junior scientists and those from under-represented minority groups, the conference provides unparalled opportunities to meet and interact with mid-level and senior investigators, offering the possibilities of new connections and career-changing opportunities. For the 2020 conference, planned presenters are all distinguished leaders in their fields, including NIH institute directors, university department chairs, center directors and others whose fields include neuroscience, psychology, economics, epidemiology, genetics, and treatment. Planned presentation topics include cannabis and opioid policy, substance use epidemiology by age, sex and race/ethnicity, neurofunctioning, genetics, the Adolescent Brain & Cognitive Development (ABCD) study, DSM-5-TR and ICD- 11 developments, serious substance consequences (psychosis, suicide), laboratory studies of drug and alcohol effects, and addiction treatments and their dissemination. Many activities are designed for junior scientists (students, fellows, early-career investigators), e.g., a workshop, breakfast round-table with senior scientists, oral poster presentations to the entire APPA audience, and meeting mentorship. Funds are requested primarily for travel awards to provide the benefits of 2020 APPA attendance to junior scientists and investigators from under- represented minority groups who could nor otherwise attend the meeting. Attendance is designed to attract junior scientists to become members of the next generation of substance abuse researchers, and members of under- represented groups to become involved in substance abuse research, benefitting the entire research community. Funds for travel expenses of distinguished non-local speakers are also requested to facilitate the conference.